Improvement of large power system with facts devices placement to maxim-IZE the system load ability

2018 ◽  
Vol 7 (2.28) ◽  
pp. 381
Author(s):  
O L. Bekri ◽  
F Mekri

Voltage instabilities and/or collapses have been recognized as one of the major causes of power system blackouts. The main objective of this paper is to provide some solutions to prevent large power systems from voltage collapse. The FACTS (Flexible AC Transmission Sys-tems) devices placement gives new opportunities for enhancing voltage stability. The calculation of the loadability point is based on the con-tinuation power flow technique (CPF) to choosing the optimal placement of STATCOM (Static Synchronous Compensator) in order to improve voltage stability by increasing the loading parameter, maintaining bus voltages at desired level and minimizing losses in a power system network.A 39-bus New England power system is chosen as test case in order to illustrate this approach. The obtained results show the efficiency of the proposed method for the planning of the Static Synchronous Compensator optimal placement and the voltage stability enhancement.  

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3365 ◽  
Author(s):  
Lukas Wienholt ◽  
Ulf Müller ◽  
Julian Bartels

The paradigm shift of large power systems to renewable and decentralized generation raises the question of future transmission and flexibility requirements. In this work, the German power system is brought to focus through a power transmission grid model in a high spatial resolution considering the high voltage (110 kV) level. The fundamental questions of location, type, and size of future storage units are addressed through a linear optimal power flow using today’s power grid capacities and a generation portfolio allowing a 66% generation share of renewable energy. The results of the optimization indicate that for reaching a renewable energy generation share of 53% with this set-up, a few central storage units with a relatively low overall additional storage capacity of around 1.6 GW are required. By adding a constraint of achieving a renewable generation share of at least 66%, storage capacities increase to almost eight times the original capacity. A comparison with the German grid development plan, which provided the basis for the power generation data, showed that despite the non-consideration of transmission grid extension, moderate additional storage capacities lead to a feasible power system. However, the achievement of a comparable renewable generation share provokes a significant investment in additional storage capacities.


Author(s):  
Raja Masood Larik ◽  
Mohd. Wazir Mustafa ◽  
Manoj Kumar Panjwani

<p>Despite a tremendous development in optimal power flow (OPF), owing to the obvious complexity, non-linearity and unwieldy size of the large interconnected power systems, several problems remain unanswered in the existing methods of OPF. Seizing specific topics for maximizing voltage stability margin and its implementation, a detailed literature survey discussing the existing methods of solution and their drawbacks is presented in this research. The phenomenon of voltage collapse in power systems, methods to investigate voltage collapse, and methods related to voltage stability are briefly surveyed. Finally, the study presents a statistical method for analyzing a power system through eigenvalue analysis in relation to the singular values of the load flow Jacobian. Future study may focus on changes in theories in conjunction with large power systems.</p>


Power system is a largely inter connected network, due to this interconnection some of the lines may get over loaded and voltage collapse will occur , hence these lines are called weak lines, this causes serious voltage instability at the particular lines of the power system. The improvement of stability will achieve by controlling the reactive power flow. The Flexible Alternating Current Transmission Systems (FACTS) devices have been proposed to effectively controlling the power flow in the lines and to regulate the bus voltages in electrical power systems, resulting in an increased power transfer capability, low system losses and improved stability. In FACTS devices the Unified Power Flow Controller (UPFC) is one of the most promising device for power flow control. It can either simultaneously or selectively control both real and reactive flow and bus voltage. UPFC is a combination of shunt and series compensating devices. Optimal location of UPFC is determined based on Voltage Stability Index (VSI). GA and PSO techniques are used to set the parameters of UPFC [6]. The objective function formulated here is fitness function, which has to be maximized for net saving. The results obtained using PSO on IEEE 14 Bus is compared with that of results obtained using GA, to show the validity of the proposed techniques and for comparison purposes


2020 ◽  
Vol 23 (2) ◽  
pp. 49-58
Author(s):  
Melat K. Abdulla ◽  
Lokman H. Hassan

Solar Photovoltaic Generators (SPVGs) play a great and vital role in providing clean and enough energy to meet power loads. However, SPVGs integration on power systems increase power grid problems. It will lead to different problems including disturbance of the grid, instability of the voltage and swings of the power. The impact of SPVG on the voltage stability of the system is studied in this paper. The best location of SPVG is obtained using three static techniques. Power flow and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under nominal load condition respectively. On other hand, Continuation Power Flow (CPF) and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under heavy load condition respectively. The proposed techniques are apllied to the New England 39-bus standard system under various loading conditions. The results reveal that choosing a proper location for the SPVG will improve the voltage stability of the system. In addition, connecting the SPVG at the nearest bus to the weakest bus provides better performance than when it connected to the weakest bus.


Flexible AC transmission systems (FACTS) devices are integrated into power system networks to control power flow, increase transmission line capability to its thermal limit, and improve the security of transmission systems. Power flow is an important mathematical calculation for planning, operation, and control of power systems network. The focus of the chapter is to explore how to modify Newton-Raphson power flow method to include various FACTS devices such as static VAR compensator (SVC), static synchronous compensator (STATCOM), static synchronous series compensator (SSSC), thyristor-controlled series capacitor (TCSC), thyristor-controlled phase shifter (TCPS), unified power flow controller (UPFC) controllers. This chapter briefly describes the power flow equations of the aforesaid FACTS-based power system network, and how the conventional power flow calculation is systematically extended to include these controllers is also been discussed.


2019 ◽  
Vol 8 (4) ◽  
pp. 3309-3324

The complexity of a power system operating with transient stability/security constraints increases with increased interconnection of power transmission networks. Many of the power system’s secure operations are affected with the voltage/transient instability problems. Thereby, the modern power systems have considered solving optimal power flow (OPF) problems using voltage/transient stability constraints as a tedious and challenging task. Algebraic and differential equations of the voltage/stability constraints are included in non-linear optimal power flow optimization problems. In this work, the OPF problems with voltage/stability constraints are solved using a newly developed reliable and robust technique. Moreover, the impact of a FACTS device such as STATCOM device was investigated to test its impact in the enhancement of power system performance. An adaptive unified differential evolution (AuDE) technique is proposed to search in the non-convex and nonlinear problems to obtain the global optimal solutions. Compared to other existing methods and basic DE, the proposed AuDE algorithm has achieved better results under simulation conditions. The power system’s performance is considerably enhanced with STATCOM device. Efficiency of the proposed method in solving the transient and security constrained power systems for optimal operations were demonstrated using the numerical results obtained from IEEE 39-bus, 10-generator system and IEEE 30-bus, 6-generator system. Due to page limitation only 30-bus systems results are presented.


2014 ◽  
Vol 984-985 ◽  
pp. 1286-1294
Author(s):  
R. Arun Prasath ◽  
M. Vimalraj ◽  
M. Riyas Ahamed ◽  
K. Srinivasa Rao

This paper presents a graphical user interface (GUI) uses Particle Swarm Optimization (PSO), which is used to find the optimal locations and sizing parameters of multi type Flexible AC transmission systems (FACTS) devices in complex power systems. The GUI toolbox, offers user to choose a power system network, PSO settings and the type and number of FACTS devices for the selected network. In this paper, three different FACTS devices are implemented: SVC, TCSC and TCPST. FACTS devices are used to increase the system loadability, by reducing power flow on overloaded lines, transmission line losses, improving system stability and security. With this can make the transmission system more energy-efficient. PSO used here for optimally allocating and sizing the multiple type FACTS in a standardized power network (IEEE 30 bus system) in order to improve voltage profile, minimizing power system total losses and maximizing system loadability with respect to the size of FACTS.


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